Black trisazo dyestuffs and their production



Patented Nov. 22, 1932 UNITED STATES ACHILLE CONZETTI, OF BASEL, SWITZERLAND, ASSIGNOR TO THE FIRMI J. R.

V S. A., 013' IBASEL,'

Garey SWITZERLAND Q BLACK TRISAZO DYESTUFFS A ND'TBEIRPRQDUGTION No Drawing. Application filed December 30, 1931, Serial No 584,008, and. inpfierm any January 1531.

According to this invention particularly valuable black trisazo dyestuffs are made by; combining with a substitution product of 2- aminonaphthalene which contains in 6- or 7 -position an amino group. or hydroxyl group, but contains no sulphonic acid group, in an alkaline medium, a diazo compound of 1 an amino-disazo dyestuff made by coupling a monodiazo compound with a monoazo dye- I vention:

stuff obtainable by coupling a 4:4.-tetrazodiphenyl with an equimolecular proportion of 1-amino-8-hydroxynaphthalene-3: 6 disulphonic. acid in an acid medium.

The dyestuffs obtainable in accordance with the invention have the following formula OaH

SOaH

NH: wherein Xrepresents an amino group or a hydroxyl group. They dye cotton, W001,"

artificial silk, silk and mixed fabrics thereof deep greenish-black or bluish-black shades;

The new dyestuffs are distinguished from v p Example 1 1 V 18.4 kilos of benzidine are tetrazotized in the usual manner and coupled in presence of;

mineral acid, such as hydrochloric or su'l phuric acid,-with 24.1 kilos of 1:8-aminonaphthol 3 6 '-disulphonic acid (mono-sodium salt) When the formation of the intermediate product is 'completed',-it is combined in a solution alkaline with sodium carbonate wlth a diazo benzene solution prepared from f9.3 kilosj of aniline. soon as the diazo benzene has'disappe'ared there is run iniall at once a solution OfltikllOS of "2z7-naphthyleneajliamiiie in ,250 litres of water and 15 kilos of concentrated hydrochloric acid.

customary manner. It dyes cotton, wool,

PATENTIOFFIcE -1 'After; the whole has been stirred jdur'ing severalhou'rs the dyestuff is worked up in the artificial silk, silk and'mixed fabrics thereof 7 deep greenish-black'shades which are com- 1 I pletely fastto vacid. 11' v scribed tution h l I (acid) (alkaline) is mixed all at once witha solution prepared in 200 litres of water with the aid of caustic soda solution. "Onr the following day the whole is heated to 40 Ctand the dyestuff is usual manner. 1 7

analogous manner when there are: "used tetr'azo compounds of :other paradianunes,

blue- 7 1 76 The intermediate product prepared as de- Example 1 and having the constiby dissolving 15.9 kilos of 2: 7-aminonaphthol 7 isolated-by 'salting out and worked up in the The dyestuff dyes cotton, wool, artificial I "silk, silk and mixedfabrics thereof deep 7 black shades completely fast toacid;

Theiinvention'may be carried out in an suclija'sfforinstance dianisidine, a substituted lzY-tetrazodiphenyl, etc. Instead of diazo benzene theremay be used other mono-di azoaryl compounds, such as for example the diazo compounds of chloraniline, toluidine and homologues thereof. p s

WVhat'I claim is "1; A process forthe manufacture of black.

trisazo dyestuffs, consisting in coupling a.

monodiazo' compound 'of the benzene series with a monoazo dyestufi obtained'from a tetrazotized paradiamine and l-aminofshydroxynaphthalene-3 6-disulphonic acid in an acid medium and combinin the intermedi'ate diazo compound [thus 0 tained in an alkaline solution. with a substitution product of Q-amino-naphthalene containing in one of positions 6 and 7 an amino or hydroxyl group, but containing, no sulphonic acid g p g a a i 2. A process for the manufacture of black trisazo dyestufi's, consisting in coupling a monodiazo compound of the benzene series With a monoazo dyestufl obtained from tetrazotized benzidineand l-amino-8-hydroxyj naphthalene-3 6-disulphonic acid in an acid medium and combining the intermediate diazo compound thus obtainedin an alkaline solution with a substitution product of 2- amino-naphthalene containing in one of posio tions'6 and 7 an amino or hydroxyl group, butcontaining no sulphonic acid group. 3. The hereinbefore described trisazo dyestufi's from a combination of a substitution a product of 2-aminonaphthalene containing in a one ofipositio'ns 6 and 7 anamino or hydroxyl 1 group, but containing no sulphonic acid group, with a diazo compoundobtained by means of a monodiaz'o compound and a mono- 7 azo dyestuif from a iz tetrazodiphenyl and wherein X represents an amino group or a formula:

1- r amino 8 hydrOxynaphthalene-S i 6-disu1- phonic acid, said dyestufis having the NH: i

hydroxyl group, and dyeing cotton, wool, artificial silk, silk and mixed fabrics thereof deep greenishi-black'to bluish-black shades,

being completely fast to acids and alkalies.

' In'witness whereof I have hereunto signed my name this 18th day, of December,'1931;

, V AGHILLE GONZETTI. 

